Add missing import to staging report generator

Change-Id: I2ceaac45b34b69a7dddaab4d60f2f0f7db1c5602

scripts/GenerateStagingReport.py

@@ -1,6 +1,7 @@
 #coding=UTF-8
 
 from BuildArchetypes import archetypes, getDeploymentContext
+from BuildDemos import demos
 import argparse, cgi
 
 parser = argparse.ArgumentParser(description="Build report generator")